Chemisorption

About: Chemisorption is a research topic. Over the lifetime, 16298 publications have been published within this topic receiving 554989 citations.

Adsorption of divalent metal ions from aqueous solutions using graphene oxide

Abstract: The adsorptive properties of graphene oxide (GO) towards divalent metal ions (copper, zinc, cadmium and lead) were investigated GO prepared through the oxidation of graphite using potassium dichromate was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FT-IR) The results of batch experiments and measurements by flame atomic absorption spectrometry (F-AAS) indicate that maximum adsorption can be achieved in broad pH ranges: 3–7 for Cu(II), 5–8 for Zn(II), 4–8 for Cd(II), 3–7 for Pb(II) The maximum adsorption capacities of Cu(II), Zn(II), Cd(II) and Pb(II) on GO at pH = 5 are 294, 345, 530, 1119 mg g−1, respectively The competitive adsorption experiments showed the affinity in the order of Pb(II) > Cu(II) ≫ Cd(II) > Zn(II) Adsorption isotherms and kinetic studies suggest that sorption of metal ions on GO nanosheets is monolayer coverage and adsorption is controlled by chemical adsorption involving the strong surface complexation of metal ions with the oxygen-containing groups on the surface of GO Chemisorption was confirmed by XPS (binding energy and shape of O1s and C1s peaks) of GO with adsorbed metal ions The adsorption experiments show that the dispersibility of GO in water changes remarkably after complexation of metal ions After adsorption, the tendency to agglomerate and precipitate is observed Excellent dispersibility of GO and strong tendency of GO–Me(II) to precipitate open the path to removal of heavy metals from water solution Potential application of GO in analytical chemistry as a solid sorbent for preconcentration of trace elements and in heavy metal ion pollution cleanup results from its maximum adsorption capacities that are much higher than those of any of the currently reported sorbents

A Nitrogen and Sulfur Dual-Doped Carbon Derived from Polyrhodanine@Cellulose for Advanced Lithium–Sulfur Batteries

Abstract: A sulfur electrode exhibiting strong polysulfide chemisorption using a porous N, S dual-doped carbon is reported. The synergistic functionalization from the N and S heteroatoms dramatically modifies the electron density distribution and leads to much stronger polysulfide binding. X-ray photoelectron spectroscopy studies combined with ab initio calculations reveal strong Li(+) -N and Sn (2-) -S interactions. The sulfur electrodes exhibit an ultralow capacity fading of 0.052% per cycle over 1100 cycles.

Tuning Oxygen Vacancies in Ultrathin TiO2 Nanosheets to Boost Photocatalytic Nitrogen Fixation up to 700 nm

Abstract: Dinitrogen reduction to ammonia using transition metal catalysts is central to both the chemical industry and the Earth's nitrogen cycle. In the Haber-Bosch process, a metallic iron catalyst and high temperatures (400 °C) and pressures (200 atm) are necessary to activate and cleave NN bonds, motivating the search for alternative catalysts that can transform N2 to NH3 under far milder reaction conditions. Here, the successful hydrothermal synthesis of ultrathin TiO2 nanosheets with an abundance of oxygen vacancies and intrinsic compressive strain, achieved through a facile copper-doping strategy, is reported. These defect-rich ultrathin anatase nanosheets exhibit remarkable and stable performance for photocatalytic reduction of N2 to NH3 in water, exhibiting photoactivity up to 700 nm. The oxygen vacancies and strain effect allow strong chemisorption and activation of molecular N2 and water, resulting in unusually high rates of NH3 evolution under visible-light irradiation. Therefore, this study offers a promising and sustainable route for the fixation of atmospheric N2 using solar energy.